Month: November 2020
Optimizing the tie-breaker regression discontinuity design
Also known as “how to approve a vaccine and still continue with stage III trials.” From Art B. Owen and Hal Varian:
Motivated by customer loyalty plans and scholarship programs, we study tie-breaker designs which are hybrids of randomized controlled trials (RCTs) and regression discontinuity designs (RDDs). We quantify the statistical efficiency of a tie-breaker design in which a proportion Δ of observed subjects are in the RCT. In a two line regression, statistical efficiency increases monotonically with Δ, so efficiency is maximized by an RCT. We point to additional advantages of tie-breakers versus RDD: for a nonparametric regression the boundary bias is much less severe and for quadratic regression, the variance is greatly reduced. For a two line model we can quantify the short term value of the treatment allocation and this comparison favors smaller Δ with the RDD being best. We solve for the optimal tradeoff between these exploration and exploitation goals. The usual tie-breaker design applies an RCT on the middle Δ subjects as ranked by the assignment variable. We quantify the efficiency of other designs such as experimenting only in the second decile from the top. We also show that in some general parametric models a Monte Carlo evaluation can be replaced by matrix algebra.
Published version here. Whether or not you agree with that particular approach, you can view 2020 in the following terms. Public health experts have told us that:
1. We citizens have to lock down many of our schools and sometimes jobs.
2. We citizens have to significantly change many of our commercial and retail and travel habits.
3. We citizens have to significantly limit or cut off many of our contacts with other human beings.
At the same time, they also are saying that:
4. “We public health experts do not have to come up with a way of approving a vaccine and simultaneously continuing to conduct our other clinical trials.”
And they wonder why people do not have greater faith in science.
How are things in North Jutland these days?
Prime Minister Mette Frederiksen announced special restrictions for more than 280,000 people in the north of Denmark on Thursday after a mutated version of the new coronavirus linked to mink farms was found in humans.
Copenhagen warned that the mutation could threaten the effectiveness of any future vaccine.
“From tonight, citizens in seven areas of North Jutland are strongly encouraged to stay in their area to prevent the spread of infection,” Frederiksen told a news conference, adding that people were being ordered not to travel there, while bars and restaurants would also shut.
“We are asking you in North Jutland to do something completely extraordinary,” Frederiksen said, talking of a “real closure” of the region.
“The eyes of the world are on us,” she added.
Here is the story, here is further analysis, and some analysis from bioscientists, does anyone know more?
The local amenities effect of Prohibition
Comparing same-state early and late adopters of county dry laws in a difference-in-differences design, we find that early Prohibition adoption increased population and farm real estate values. Moreover, we find strong effects on farm productivity consistent with increased investment due to a land price channel. In equilibrium, the amenity change disproportionately attracted immigrants and African-Americans.
That is from a new paper by Greg Howard and Arianna Ornaghi, revise and resubmit at Journal of Economic History. Arianna is on the job market from MIT, here is her job market paper and broader portfolio. Here is her paper on civil service reforms for U.S. police departments.
Thursday assorted links
1. Novovax: did you have moth cells and Gaithersburg on your 2020 bingo card?
2. And here is one version of the Danish mink news. Its import remains unclear.
3. Mongolian heavy metal video with 60 million views, good visuals and lyrics too.
4. Carolyn Stein papers on the economics of science and the biosciences. She is an economics job market candidate from MIT.
5. Married vs. unmarried women. And how Stanford voted.
6. Why electoral fraud is difficult (NYT).
Efficiency wages for warehouse workers
The firm gains $1.10 from increased productivity for a $1 increase in wages.
And:
…we estimate that over half of the turnover reductions and productivity increases arise from behavioral responses as opposed to compositional differences. These aggregate patterns mask considerable heterogeneity by gender: women’s productivity responds more and their turnover responds less to wage changes than men’s, which can lead to occupational pay gaps.
That is from a new paper by Natalia Emanuel, a job market candidate from Harvard University. The paper is co-authored with Emma Harrington (also on the job market), here is their other paper on the efficiencies and inefficiencies of working from home.
I had previously reported on Natalia’s very good paper, with Valentin Bolotnyy, on why women are paid less.
She has work in progress on school closures and family violence: “After three-day weekends and snow-days, reports of family violence increase. I further show that these effects are concentrated in counties with low median income.”
Social Media Usage and the Level of Depressive Symptoms in the United States
I find that using Twitter decreases the level of depressive symptoms by 27%.
That is from the job market paper of Qin Jiang from USC. Via Jennifer Doleac.
Rising Ethnic Diversity in the United States Accompanies Shifts Toward an Individualistic Culture
This is consistent with some claims by Bryan Caplan, and perhaps contra what used to be called the new Democratic demographic strategy:
We investigate the relationship between ethnic diversity and the rise of individualism in the United States during the 20th and 21st centuries. Tests of the historical rates of ethnic diversity alongside individualistic relational structures (e.g., adults living alone, single-/multi-child families) from the years 1950 to 2018 reveal that societal and regional rates of ethnic diversity accompanied individualistic relational structures. These effects hold above and beyond time-series trends in each variable. Further evidence from experimental studies (N = 707) suggests that the presence of, and contact with, ethnically diverse others contributes to greater individualistic values (e.g., the importance of uniqueness and personal achievement). Converging evidence across societal-, regional-, and individual-level analyses suggests a systematic link between ethnic diversity and individualism. We discuss the implications of these findings for sociocultural livelihood in light of the rising rates of ethnic diversity across the globe.
That is from a new paper by Alex C. Huynh and Igor Grossman. Via the excellent Kevin Lewis.
My Conversation with Edwidge Danticat
Here is the audio, video, and transcript. Here is the CWT summary:
She joined Tyler to discuss the reasons Haitian identity and culture will likely persist in America, the vibrant Haitian art scenes, why Haiti has the best food in the Caribbean, how radio is remaining central to Haitian politics, why teaching in Creole would improve Haitian schools, what’s special about the painted tap-taps, how tourism influenced Haitian art, working with Jonathan Demme, how the CDC destroyed the Haitian tourism industry, her perspective on the Black Lives Matter movement, why she writes better at night, the hard lessons of Haiti’s political history, and more.
Here is one excerpt:
COWEN: Now, in all of these conversations, there’s a segment where I present to the guest my favorite Haitian proverbs, and he or she reacts. Are you ready for a few?
DANTICAT: All right. You’ve been sharing Haitian proverbs with your guests?
COWEN: Here’s one. “After the dance, the drum is heavy.”
DANTICAT: Oh my god.
COWEN: What does that mean to you?
DANTICAT: Aprè dans, tanbou lou. I actually have a book called After the Dance. It’s on Carnival. Yes, for me, it means that there are consequences to everything, even the most joyful thing. You have to be prepared for the consequences of things that you’ve done.
It’s something that my mom used to say quite a bit, too. If you have just had a really big celebration, or if you waited too late to do your homework because you’re having a good time watching a program you like, she was like, “Aprè dans, tanbou lou.” After the dance, the drum is heavy. It’s like the morning-after, hangover situation and the most joyful outcome, but really, that there are consequences to everything.
COWEN: Here’s another one. “It is the owner of the body who looks out for the body.”
DANTICAT: Oh, this one. You will not believe how much we hear that these days. Se mèt kò ki veye kò. It’s something that we say a lot now in the coronavirus era. You hear it on the radio. You hear people say it when they talk to their neighbors. Se mèt kò ki veye kò. That means that, really, you are the best person to take care of yourself.
If you’re saying, “Wear your mask when you go out during the coronavirus era.” “Wash your hands.” It’s like the best, the most qualified person to take care of you is you. It’s not the doctor. It’s not your loved one. Se mèt kò ki veye kò. It’s the owner of the body who takes care of the body. It’s like, “Watch out for yourself.” It’s very good advice these days.
COWEN: “When they want to kill a dog, they say it’s crazy.”
DANTICAT: Yes, that’s the dehumanization. I guess that’s fake news. [laughs] It’s connected to the fake news. If you want to diminish or slight someone, you call them names. So that’s also a timely one, I think.
COWEN: How about this one? “The constitution is paper; the bayonet is steel.”
DANTICAT: Yes. Again, back to our conversation about dictatorship, in a way. I believe that one was often cited by one of the generals, actually, during the ’90s, during the coup d’état, or it might have been even before. I think it speaks to the fragility of documents like the constitution. Yesterday was Constitution Day in the US, so that might also apply here.
It’s that whole thing with freedom. Freedom is something that we have to always keep watching out it doesn’t slip away because, sometimes, we think these documents or these rules are set in stone. I think this general who kept saying this was saying, “Well, I have the weapons.” It’s kind of paper, rock scissors. Which is stronger?
COWEN: “When the mapou tree dies, goats would eat its leaves.”
DANTICAT: Yes. This one, I think, is about humility because we have this expression that we say when someone has died who has contributed a great deal to our culture: we say that a mapou has fallen. A mapou is a soft cotton tree, it’s a kind of sacred tree, and it’s also a big tree that lasts forever. It’s a regal institution, a mapou.
What this one is saying, actually, the goat is a meager creature compared to a mapou, and there’s no way a goat would actually be able to access the leaves of a mapou, but when it dies, it falls. I’ve always heard that proverb as a way of encouraging humility, that all our leaves are vulnerable to the goat, if you will. [laughs]
COWEN: One more proverb, “Beyond the mountain is another mountain.”
DANTICAT: Yes. Dèyè mòn gen mòn.
COWEN: That’s a very famous one.
DANTICAT: Yes. I actually use that a lot myself. One of my neighbors just passed away, and she used to use that proverb a lot. I think it means that no matter what, we can see there is more. I think it’s about there’s more to everything than what we see.
It also speaks to the physical layout of Haiti because it’s a very mountainous place. Ayiti. The Arawak called it Ayiti. It actually means land of the mountains, and it’s physically true. If you’re traveling across Haiti, literally, there’s always a mountain physically behind a mountain, but in a spiritual sense, it also means that there’s always more.
Recommended. And I thank Carl-Henri Prophète for assistance with the transcription.
Wednesday assorted links
1. My 2016 post on the coalition for diversity.
2. Oregon votes to decriminalize heroin, meth, and other street drugs. Here are other drug results.
3. “Alyce Swinbourne, an expert in wombat bottoms from the University of Adelaide…”
4. Explainer on how the Dutch whale tail saved the train.
5. Joseph Walker Australian podcast with me, lots on philosophy and Stubborn Attachments and real estate bubbles.
6. Caveat emptor, but if you are looking for a new “Hail Mary” against Covid, how about honey and Nigella sativa? It’s a Pakistani RCT.
The Economics of Sex Robots
Diana Fleischman analyzes the economics of sex robots.
When the sex ratio changes, so too do sexual norms; sex robots are going to emulate an increase in the ratio of women to men. Contrary to a prediction based on the idea that men would wield greater patriachal control if they were in higher numbers, a larger percentage of women relative to men on University campuses is associated with women who are more likely to have casual sex and less likely to be virgins. When there are more men than women, women are much less likely to have casual sex. The majority sex (in this case men) competes for the minority sex (in this case women) and the minority sex calls the shots. When there is a female majority in the population, women compete for access to mates with casual sex. Whereas a male majority competing for access to scarce women compete with long-term commitment.
Sex robots will emulate a majority women ratio, shifting women to compete for men’s attention by requiring less courtship and commitment in exchange for sex. The long-term ramifications are unclear, especially the way long-term technologies and cultural norms will interact. Perhaps women will discover they have to make the costs of courtship both low and transparent to compete with sex robots. Or, perhaps, new technology could enable women to recombine their genes with one another, making men enamored with sex robots (or men generally) totally redundant.
Much more of interest at the link.
When will vaccine tourism come?
That is the topic of my Bloomberg column, here is one excerpt:
It is now possible to have a decent sense of which nation is winning the vaccine race, and it is not the U.S. A Chinese vaccine is being distributed now, and so far it seems to be safe and modestly effective. The data are not sufficiently clear that you ought to get one now, but it is easy to imagine that in another month or two the Chinese vaccine will be a plausible option.
And no, you probably won’t have to go to China for the jab. The Chinese vaccines are being distributed on a global basis, and are already in extensive tests in the United Arab Emirates. The timing is uncertain, but with delays on the U.S. side it is entirely possible that come January you will be able to get a “good enough” vaccine in Dubai but not in Dallas.
So would you get on that plane?
And:
You might think there will be complicated allocation rules limiting your ability, as a foreigner, to have access to these vaccines. That is likely true, but there is also going to be slippage. Say you are a front-line nurse overseas, and you already had Covid back in March. The private clinic you work for will be able to order a vaccine on your behalf, but then turn around and sell it to a visiting foreigner for, say, $20,000.
There is much more at the link.
Love and Liberty: A Short History of Adam Smith in Love
The author devotes his full scholarly attention to the mystery of Adam Smith’s love life by carefully re-assembling all the admissible amorous evidence, by subjecting such facts to critical lawyerly scrutiny, and by drawing reasonable inferences from these sundry proofs. Part 1 of this paper will set the stage by revisiting several intriguing hypotheses concerning Doctor Smith’s sexuality and romantic attachments. Next, Part 2 presents four pieces of evidence regarding Adam Smith’s lost loves: (i) an obscure but intriguing footnote in Dugald Stewart’s 1793 biography of Smith’s life and writings, (ii) a letter dated July 14, 1784 addressed to Professor Stewart, (iii) a brief anecdote by Henry Mackenzie, a prominent Scottish lawyer and writer, as well as (iv) a letter dated 18 September 1766 containing key corroborating details about Adam Smith’s lost loves. Part 3 then speculates about the whereabouts of Adam Smith’s lost diary and also about why Smith instructed his literary executors as early as 1773 to destroy his private papers and correspondence. Next, Parts 4 and 5 of this paper will consider two additional clues that may shed light on this amorous enigma. Specifically, Part 4 will revisit Adam Smith’s analysis of romantic love in The Theory of Moral Sentiments, while Part 5 will discuss the legal and ecclesiastical regulation of sex in 18th Century Scotland and France–the locales of Smith’s love affairs. Part 6 then presents one last and potentially relevant clue: the notorious case of the Chevalier de La Barre, which played out during Adam Smith’s sojourns in Paris and Abbeville, and Part 7 concludes with observations for future research. In short, contrary to the conventional biographical wisdom, reports of Adam Smith’s love life are not mere rumors or unfounded speculations. Although Adam Smith’s lifelong devotion to his intellectual life and to his widowed mother Margaret Douglas may have ultimately prevented him from getting married and forming his own household, the evidence will show that it is “more likely than not” that Adam Smith was deeply in love at least twice in his life.
That is a new working paper by F.E. Guerra-Pujol.
Hey you people, part II
Here is another outlet for you poor, poor people…
Hey you people
If you want to talk about today, put your comments here, you poor people…
Tuesday assorted links
1. “In Sweden we have this phenomenon called Jantelagen. It’s when someone is famous, and the people around use up all their energy to ignore the fact that the person is famous.” (NYT link here)
3. New and significant results on working remotely, very good paper: fine for gains from trade, lower productivity outweighed by worker gains, still negative adverse selection associated with the practice as a whole. Author Emma Harrington is on the job market from Harvard.
4. New, long paper developing a better cyclically-adjusted measure of TFP. TFP is still falling, but more gradually than under alternate measures. For Europe the revisions make less of a difference.
5. Good summary of some Fast Grants-supported research on Interferon.
6. Daniel Gross is bullish on Starlink.